The subject invention is directed generally to DC to DC converters, and more particularly to an improved DC to DC converter that utilizes a fixed switching frequency and employs a non-saturating magnetic amplifier controller to control the voltage of the converter.
DC to DC converters are utilized in applications wherein the output of a source DC voltage needs to be converted to a DC supply voltage of a different voltage level. Typically, the source DC voltage is converted to an AC voltage by some form of switching circuitry. The AC voltage is stepped up or down as required, and then rectified to provide the DC supply voltage. For reasons associated with switching loss and noise generation it is often desirable to utilize approximately sinusoidal waveforms for the AC portion of a DC to DC converter, and the DC to DC converters disclosed herein utilize approximately sinusoidal waveforms in their respective AC portions.
The output voltage of a switching DC to DC converter that utilizes approximately sinusoidal waveforms in its AC portion is typically controlled by varying switching frequency. A consideration with varying switching frequency for voltage regulation is that many devices that may be used as a load on the rectifier circuit of a DC to DC converter are very sensitive to ripple out of the rectifier circuit. To alleviate noise sensitivity, special techniques are used to filter out ripple, but such techniques require ripple to be at a fixed frequency and thus are not suitable for use with DC to DC converters that vary frequency to achieve output voltage control.